One of the major demands for further Computer Tomography (CT) applications is to scan a heart during its passive state. Necessary for that is a faster gantry rotation and hence a shorter but higher x-ray power pulse. These power peaks are hard to realize with commonly used x-ray tubes. Computed tomography (CT) is a process of using digital processing to generate a three-dimensional image of the internal of an object under investigation (object of interest, object under examination). The reconstruction of CT images can be done by applying appropriate algorithms.